We propose to utilize a series of compounds first developed as plant hormone antagonists to study the chemical basis of the cell division and differentiation processes in both plants and animals, and to simultaneously create potent agents for cancer chemotherapy. This approach is feasible because those structural features which correlate with intense anticytokinin activity, also result in compounds most active in suppressing the growth of transformed human lymphocytes. It is anticipated that these compounds may be active at very low concentration levels in plant and animal systems, and that they might therefore function effectively as chemotherapeutic agents in mammalian systems with minimal side effects.